This invention relates to electrical totalizers and more particularly to totalizers which combine pulses representing power being consumed from two or more different sources and provide output pulses representative of the total power consumed.
Pulse devices are used in watthour and varhour meters by power companies and industry to provide pulses, the number of which is proportional to the power being consumed. The pulses are used for billing purposes as well as for load management programs. The power companies record signals representing the power consumed for subsequent billing to the customer. Billing is made according to the peak energy used during some finite time interval, i.e., 15 minutes, as well as by the time of day that the peak energy usage occurred. Industrial users employ the pulses as input to computers for load management programs.
Where two or more circuits are involved, each circuit carries a separate series of pulses representative of the power being consumed for the corresponding circuit. Totalizers are known which totalize the pulses from separate circuits into a single channel of totalized pulses for purposes of recording. In this regard, the single channel of totalized pulses is commonly recorded on a real time basis on magnetic tape in the form of non return to zero (NRZ) recording. Each transition in flux on the magnetic tape represents a unit of power consumed. The recorded pulses are later utilized to determine the peak power consumption during any desired time interval during the day. It is a characteristic of this type of recording equipment that there be some predetermined minimum time interval between two successive flux changes or pulses recorded along the tape. The problem of totalizing is complicated by the fact that the pulses in one circuit may occur simultaneously, overlap, or occur at most any time separation in relation to the pulses in the other circuit. Also, there may be bursts of power usage where two pulses in one circuit may occur very close together.
Totalizers are known for totalizing multiple circuits of power pulses into a single channel of pulses for recording on tape. One general type of totalizer of this type now in use is referred to as the MD totalizer manufactured by The General Electric Company and described in General Electric brochure GEH-1050F published May, 1969. The MD type totalizer utilizes synchronous motors driving a differential drive gear assembly. Another type of device manufactured by The General Electric Company is referred to as the type SST-3 Solid state Totalizer and is described in General Electric brochure GEH-2784A, published April, 1973.
These prior art types of totalizers suffer from a number of disadvantages.